1. Field of the Invention
The present invention relates to a structure of rotation shaft, more particularly to a structure of supporting rotation shaft which can be served as a supporting rack for a rear portion of an object to be supported and the tilting angle of the object to be supported is capable of being adjusted.
2. Description of Related Art
Two connected members having a relative connection angle are commonly seen and used in now days, such as door sheets; opening and closing two members are often defined as in an operating status and a non-operating status, e.g. a note book computer, an electronic dictionary, a portable audio/video displaying device.
The device whose relative angle can be adjusted often is mainly composed by a hinge; when applied to the note book computer mentioned above, the device is defined as a rotation shaft or a hinge device; regardless the definition of the device, theories of torque and friction are utilized in the device, the two members are respective provided with an engaging assembly that can be engaged to each other, such as a friction member or a cam member, and positioning of the open/close status is achieved by the two members engaging with each other.
A flat panel monitor, e.g. a liquid crystal monitor, a liquid crystal television or a plasma television, has advantages of light in weight, thin in thickness and no radiation, so a conventional CRT monitor is mostly replaced by the flat panel monitor. A supporting structure having a structure of rotation shaft is a must-have accessory for a flat panel monitor. The supporting structure often has a base seat on which a supporting rack is provided, and the structure of rotation shaft is provided between the flat panel monitor and the supporting rack, so the tilting angle of the flat panel monitor is capable of being adjusted.
A flat panel monitor can also be used as a displaying device that is equipped in a digital photo frame, the back portion of the digital photo frame usually has a retractable supporting rack so the digital phone frame can be tilted with an angle so as to stand on a table. But the fashion of the supporting rack connecting to the digital photo frame is a simple pivotal connection so only an open/close function can be provided, such art can be used in a small-size digital photo frame. But for one with a larger size, e.g. a 15-inch flat panel monitor or even a bigger one, the supportive rack is deemed as a bit too simple; for example, there is no resilient supporting unit provided so a function of adjusting the tilting angle is not available, so this kind of supporting rack can not be used in a big flat panel monitor. How to provide a structure of rotation shaft that has functions of storing and supporting and when applying an external force on the flat panel monitor the pivotally connected structure of rotation shaft can provide a function of adjusting the tilting angle becomes a obstacle to be overcome.